GW will bring out a codex for them eventually and it will go into great depth about who they are, where they came from, what their toughness is and how many attacks they get. GW ruins all their mysteries sooner or later. IB
Gw needs to make something happen with the dark angles, I want to know more about the jawas and the fallen, lik a book from their point of view like right before and right after they got thrown into the warp.
No they should never reveal anything else about them .... keep them a mystery. It's better that way. In fact anything that is a mystery within the 40k world should stay a mystery. GW should occassionaly drop a very subtle hint for us all to obsess over, until the next hint of course. This is what made the 40k world so great back in the day and why it has such a huge following .... and now they just keeping fucking with the lore .... revealing secrets that should just never be known. I don't want my 40k cookies square shaped and vanilla flavoured thank you very much! IB
I imagine they are part of a race that was all but exterminated by chaos. I would assume they treated Caliban like Degobah, masking their presence there with the darkness inherit to the planet.